The present invention is directed generally to a hot water dispensing apparatus, and more particularly to a hot water dispenser for dispensing large volumes of hot water at a predetermined uniform temperature.
It is frequently desirable in restaurants and other commercial cooking establishments to have a source of hot water for various cooking purposes, such as the preparation of pastas, potatoes, gravies, soups and similar dishes, as well as for various cleaning purposes. To supply hot water for these and other purposes hot water dispensers have come into increasing use. Typically, these units employ a hot water reservoir in which water is heated by an electric resistance heater element. The application of electric current to the heating element is controlled by various means responsive to the temperature of the water in the reservoir, such as a thermostat, to achieve a predetermined dispensing temperature. One successful commercial version of such a hot water dispenser is the Model HW-5 Hot Water Machine manufactured by Bunn-0-Matic Corporation of Springfield, Ill., U.S.A.
In addition, various constructions of coffee brewers have been developed which include a reservoir in which water is heated to a predetermined brewing temperature and subsequently dispensed. For example, in the coffee maker described in U.S. Pat. No. 4,413,552 to Donald L. Daugherty, heated water is displaced from the top portion, or outlet zone, of a reservoir by cold water entering the bottom portion, or inlet zone of the reservoir, and discharged onto ground coffee or tea held in a brewer funnel lined with a disposable filter. The freshlY brewed coffee or tea discharged from the brewer funnel is collected in a serving beaker.
Cold water may be admitted in a determined volume to the reservoir of such a coffee maker to displace a like volume of heated water delivered to the brewing funnel. For example, in a pour-in type beverage brewer, such as that described in the afore-identified U.S. Pat. No. 4,413,552, a volume of cold water sufficient to produce the desired volume of beverage to be brewed is admitted to the bottom of the reservoir to displace an equal volume of hot water to the brewing funnel. In automatic type beverage brewers, such as described in U.S. Pat. No. 3,793,934, a valve is opened by electrical or manual means to periodically deliver predetermined batches of like volume of cold water to the apparatus.
An improved temperature control system for such coffee brewers is shown in U.S. Pat. No. 4,531,046 to Kenneth W. Stover, wherein an electronic temperature regulating circuit is utilized in conjunction with a thermistor suspended within a hollow copper tube in a central serving zone of a reservoir to control the application of current to a resistance heating element in the reservoir.
For maximum utility, a hot water dispenser must be capable of delivering hot water at a precisely controlled temperature in the face of widely varying demands. For example, a hot water dispenser may be suddenly called upon by one user to dispense large volumes of hot water for some occasional purpose, such as cleaning, and immediately thereafter be called upon by another user to dispense hot water for a different temperature-critical purpose such as cooking. Furthermore, in the event that the temperature of the dispensed water should ever fall below an acceptable level, it is desirable that the operator be immediately alerted to the unacceptable water temperature so that he can take appropriate action.
Since the hot water dispenser may be utilized in a restaurant where operating hours may be long and other heat producing equipment may be in close proximity, it is necessary that the dispenser function with a high degree of reliablity and independence from adverse operating environments. This has been difficult to achieve because of the adjacent heat producing apparatus, which make it difficult to adequately cool electrical components utilized for temperature control. Conventional cooling means, such as finned external heat sinks, are impractical because of the space they require and the difficulty they present when cleaning. The hot water dispenser of the present invention avoids this problem by utilizing the water filled reservoir of the dispenser as a heat sink for the critical electrical components.
The present invention provides a hot water dispenser which provides not only an increased volume of hot water at a predetermined temperature, but also an unambiguous indication to the user that water being dispensed is within a range of acceptable temperatures. Furthermore, it does this with improved efficiency and reliability, even in adverse operating environments.
Accordingly, it is a general object of the present invention to provide a new and improved hot water dispenser.
It is a more specific object of the present invention to provide a hot water dispenser which dispenses an increased volume of water at a predetermined dispensing temperature.
It is another specific object of the present invention to provide a hot water dispenser which provides an unambiguous indication to a user that hot water is being dispensed within a predetermined range of temperatures.
It is another specific object of the invention to provide a hot water dispensing apparatus which provides a high degree of reliability in the adverse operating environments often encountered in restaurants and other commercial establishments.